![]() | |||||||||||||
Messages in this thread |
William Lee Irwin III wrote: >>-if ((size < 4096 || fls(size-1) == fls(size-1+3*BYTES_PER_WORD))) >>+if (size + 3*BYTES_PER_WORD <= PAGE_SIZE || On Sat, May 22, 2004 at 10:02:25AM +0200, Manfred Spraul wrote: > I understand this change: objects between 4082 and 4095 bytes are > redzoned and cause order==1 allocations, that's wrong. William Lee Irwin III wrote: > >+ ((size & (size - 1)) && > >+ (1 << fls(size)) - size > 3*BYTES_PER_WORD)) On Sat, May 22, 2004 at 10:02:25AM +0200, Manfred Spraul wrote: > Why this change? I've tested my fls(size-1)==fls(size-1-3*4) approach > and it always returned the right result: No redzoning between 8181 and > 8192 bytes, between 16373 and 16384, etc. It returns a false positive when size + 3*BYTES_PER_WORD == 2**n, e.g. size == 16373. Here, fls(size - 1) == 13, but fls(size - 1 + 12) == 13 while size - 1 + 12 == 16384, where we'd want the check to fail. Or so my analysis of it goes. -- wli - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ | ||||||||||||
| Last update: 2005-03-22 13:03 [from the cache] ©2003-2008 | |||||||||||||